The present invention relates to a fuel rail and to a method of making a fuel rail.
The following discussion of related art is provided to assist the reader in understanding the advantages of the invention, and is not to be construed as an admission that this related art is prior art to this invention.
A fuel rail is a component of the fuel supply of a motor vehicle. Fuel is injected at high pressure into a base body of the fuel rail and transferred via fuel injectors into the cylinders. The fuel rail is hereby exposed to very high pressures. One approach to address this problem involves the production of the fuel rail as forged part and using subsequent machining processes to produce a tubular base body as well as fuel inlet and injector mounts. Support elements are further provided to fasten the fuel rail to further motor vehicle parts. During operation, fuel under pressure is discharged from the base body through the fuel injectors. The injector mounts are hereby moved by the work done by the fuel injectors, while the portions of the fuel rail that are connected via the support elements with the motor vehicle remain stationary. A force is thus introduced into the fuel rail in the region of an injector mount during operation of the vehicle. While this force is dissipated via the support elements that normally are fastened to a cylinder head, the movement of the injector mounts causes deformation of the fuel rail. This poses another problem because the deformation causes seals, such as O rings, disposed between the fuel injector and the injector mount to become leaky very quickly by the continuous motion or wear off so that there is a risk of unwanted fuel egress that in a worst case scenario may ignite. Such O rings which are made of a rubber or caoutchouc material are therefore prone to leak or wear off as a result of the movement by the injector mounts and deformation of the fuel rail. Thus, tightness of the fuel is absolutely necessary to maintain for safety reasons.
While suggestions have been made to address this problem by stiffening the fuel rail through increase of the wall thickness of the fuel rail. This, however, increases also weight of the fuel rail which goes against the desire for a lightweight construction and weight savings demanded in the automobile industry.
It would therefore be desirable and advantageous to provide an improved fuel rail which obviates prior art shortcomings and which is of lightweight construction and yet is subject to minimal deformation during operation.